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Merged V1.3 to HEAD(3161:3179)

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svn merge svn://www.alfresco.org:3691/alfresco/BRANCHES/V1.3@3161 svn://www.alfresco.org:3691/alfresco/BRANCHES/V1.3@3179 .


git-svn-id: https://svn.alfresco.com/repos/alfresco-enterprise/alfresco/HEAD/root@3406 c4b6b30b-aa2e-2d43-bbcb-ca4b014f7261
This commit is contained in:
Derek Hulley
2006-07-26 10:49:21 +00:00
parent 36f219edf1
commit 595556f3c5
39 changed files with 1924 additions and 1602 deletions
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361
source/java/org/alfresco/repo/content/metadata/MetadataExtracterRegistry.java
View File

@@ -1,191 +1,172 @@
/*
* Copyright (C) 2005 Jesper Steen Møller
*
* Licensed under the Mozilla Public License version 1.1
* with a permitted attribution clause. You may obtain a
* copy of the License at
*
* http://www.alfresco.org/legal/license.txt
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
* either express or implied. See the License for the specific
* language governing permissions and limitations under the
* License.
*/
package org.alfresco.repo.content.metadata;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReadWriteLock;
import java.util.concurrent.locks.ReentrantReadWriteLock;
import org.alfresco.error.AlfrescoRuntimeException;
import org.alfresco.repo.content.MimetypeMap;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
/**
* Holds and provides the most appropriate metadate extracter for a particular
* mimetype.
* <p>
* The extracters themselves know how well they are able to extract metadata.
*
* @see org.alfresco.repo.content.metadata.MetadataExtracter
* @author Jesper Steen Møller
*/
public class MetadataExtracterRegistry
{
private static final Log logger = LogFactory.getLog(MetadataExtracterRegistry.class);
private List<MetadataExtracter> extracters;
private Map<String, MetadataExtracter> extracterCache;
private MimetypeMap mimetypeMap;
/** Controls read access to the cache */
private Lock extracterCacheReadLock;
/** controls write access to the cache */
private Lock extracterCacheWriteLock;
public MetadataExtracterRegistry()
{
// initialise lists
extracters = new ArrayList<MetadataExtracter>(10);
extracterCache = new HashMap<String, MetadataExtracter>(17);
// create lock objects for access to the cache
ReadWriteLock extractionCacheLock = new ReentrantReadWriteLock();
extracterCacheReadLock = extractionCacheLock.readLock();
extracterCacheWriteLock = extractionCacheLock.writeLock();
}
/**
* The mimetype map that will be used to check requests against
*
* @param mimetypeMap a map of mimetypes
*/
public void setMimetypeMap(MimetypeMap mimetypeMap)
{
this.mimetypeMap = mimetypeMap;
}
/**
* Register an instance of an extracter for use
*
* @param extracter an extracter
*/
public void register(MetadataExtracter extracter)
{
if (logger.isDebugEnabled())
{
logger.debug("Registering metadata extracter: " + extracter);
}
extracterCacheWriteLock.lock();
try
{
extracters.add(extracter);
extracterCache.clear();
}
finally
{
extracterCacheWriteLock.unlock();
}
}
/**
* Gets the best metadata extracter. This is a combination of the most
* reliable and the most performant extracter.
* <p>
* The result is cached for quicker access next time.
*
* @param mimetype the source MIME of the extraction
* @return Returns a metadata extracter that can extract metadata from the
* chosen MIME type.
*/
public MetadataExtracter getExtracter(String sourceMimetype)
{
// check that the mimetypes are valid
if (!mimetypeMap.getMimetypes().contains(sourceMimetype))
{
throw new AlfrescoRuntimeException("Unknown extraction source mimetype: " + sourceMimetype);
}
MetadataExtracter extracter = null;
extracterCacheReadLock.lock();
try
{
if (extracterCache.containsKey(sourceMimetype))
{
// the translation has been requested before
// it might have been null
return extracterCache.get(sourceMimetype);
}
}
finally
{
extracterCacheReadLock.unlock();
}
// the translation has not been requested before
// get a write lock on the cache
// no double check done as it is not an expensive task
extracterCacheWriteLock.lock();
try
{
// find the most suitable transformer - may be empty list
extracter = findBestExtracter(sourceMimetype);
// store the result even if it is null
extracterCache.put(sourceMimetype, extracter);
return extracter;
}
finally
{
extracterCacheWriteLock.unlock();
}
}
/**
* @param sourceMimetype The MIME type under examination
* @return The fastest of the most reliable extracters in <code>extracters</code>
* for the given MIME type, or null if none is available.
*/
private MetadataExtracter findBestExtracter(String sourceMimetype)
{
double bestReliability = -1;
long bestTime = Long.MAX_VALUE;
logger.debug("Finding best extracter for " + sourceMimetype);
MetadataExtracter bestExtracter = null;
for (MetadataExtracter ext : extracters)
{
double r = ext.getReliability(sourceMimetype);
if (r <= 0.0)
{
// extraction not achievable
continue;
}
else if (r == bestReliability)
{
long time = ext.getExtractionTime();
if (time < bestTime)
{
bestExtracter = ext;
bestTime = time;
}
}
else if (r > bestReliability)
{
bestExtracter = ext;
bestReliability = r;
bestTime = ext.getExtractionTime();
}
}
return bestExtracter;
}
/*
* Copyright (C) 2005 Jesper Steen Møller
*
* Licensed under the Mozilla Public License version 1.1
* with a permitted attribution clause. You may obtain a
* copy of the License at
*
* http://www.alfresco.org/legal/license.txt
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
* either express or implied. See the License for the specific
* language governing permissions and limitations under the
* License.
*/
package org.alfresco.repo.content.metadata;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReadWriteLock;
import java.util.concurrent.locks.ReentrantReadWriteLock;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
/**
* Holds and provides the most appropriate metadate extracter for a particular
* mimetype.
* <p>
* The extracters themselves know how well they are able to extract metadata.
*
* @see org.alfresco.repo.content.metadata.MetadataExtracter
* @author Jesper Steen Møller
*/
public class MetadataExtracterRegistry
{
private static final Log logger = LogFactory.getLog(MetadataExtracterRegistry.class);
private List<MetadataExtracter> extracters;
private Map<String, MetadataExtracter> extracterCache;
/** Controls read access to the cache */
private Lock extracterCacheReadLock;
/** controls write access to the cache */
private Lock extracterCacheWriteLock;
public MetadataExtracterRegistry()
{
// initialise lists
extracters = new ArrayList<MetadataExtracter>(10);
extracterCache = new HashMap<String, MetadataExtracter>(17);
// create lock objects for access to the cache
ReadWriteLock extractionCacheLock = new ReentrantReadWriteLock();
extracterCacheReadLock = extractionCacheLock.readLock();
extracterCacheWriteLock = extractionCacheLock.writeLock();
}
/**
* Register an instance of an extracter for use
*
* @param extracter an extracter
*/
public void register(MetadataExtracter extracter)
{
if (logger.isDebugEnabled())
{
logger.debug("Registering metadata extracter: " + extracter);
}
extracterCacheWriteLock.lock();
try
{
extracters.add(extracter);
extracterCache.clear();
}
finally
{
extracterCacheWriteLock.unlock();
}
}
/**
* Gets the best metadata extracter. This is a combination of the most
* reliable and the most performant extracter.
* <p>
* The result is cached for quicker access next time.
*
* @param mimetype the source MIME of the extraction
* @return Returns a metadata extracter that can extract metadata from the
* chosen MIME type.
*/
public MetadataExtracter getExtracter(String sourceMimetype)
{
MetadataExtracter extracter = null;
extracterCacheReadLock.lock();
try
{
if (extracterCache.containsKey(sourceMimetype))
{
// the translation has been requested before
// it might have been null
return extracterCache.get(sourceMimetype);
}
}
finally
{
extracterCacheReadLock.unlock();
}
// the translation has not been requested before
// get a write lock on the cache
// no double check done as it is not an expensive task
extracterCacheWriteLock.lock();
try
{
// find the most suitable transformer - may be empty list
extracter = findBestExtracter(sourceMimetype);
// store the result even if it is null
extracterCache.put(sourceMimetype, extracter);
return extracter;
}
finally
{
extracterCacheWriteLock.unlock();
}
}
/**
* @param sourceMimetype The MIME type under examination
* @return The fastest of the most reliable extracters in <code>extracters</code>
* for the given MIME type, or null if none is available.
*/
private MetadataExtracter findBestExtracter(String sourceMimetype)
{
double bestReliability = -1;
long bestTime = Long.MAX_VALUE;
logger.debug("Finding best extracter for " + sourceMimetype);
MetadataExtracter bestExtracter = null;
for (MetadataExtracter ext : extracters)
{
double r = ext.getReliability(sourceMimetype);
if (r <= 0.0)
{
// extraction not achievable
continue;
}
else if (r == bestReliability)
{
long time = ext.getExtractionTime();
if (time < bestTime)
{
bestExtracter = ext;
bestTime = time;
}
}
else if (r > bestReliability)
{
bestExtracter = ext;
bestReliability = r;
bestTime = ext.getExtractionTime();
}
}
return bestExtracter;
}
}